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Chuck Lever
99dc2ef039
There are one or two cases where CREATE_SESSION returns NFS4ERR_DELAY in order to force the client to wait a bit and try CREATE_SESSION again. However, after commite4469c6cc6("NFSD: Fix the NFSv4.1 CREATE_SESSION operation"), NFSD caches that response in the CREATE_SESSION slot. Thus, when the client resends the CREATE_SESSION, the server always returns the cached NFS4ERR_DELAY response rather than actually executing the request and properly recording its outcome. This blocks the client from making further progress. RFC 8881 Section 15.1.1.3 says: > If NFS4ERR_DELAY is returned on an operation other than SEQUENCE > that validly appears as the first operation of a request ... [t]he > request can be retried in full without modification. In this case > as well, the replier MUST avoid returning a response containing > NFS4ERR_DELAY as the response to an initial operation of a request > solely on the basis of its presence in the reply cache. Neither the original NFSD code nor the discussion in section 18.36.4 refer explicitly to this important requirement, so I missed it. Note also that not only must the server not cache NFS4ERR_DELAY, but it has to not advance the CREATE_SESSION slot sequence number so that it can properly recognize and accept the client's retry. Reported-by: Dai Ngo <dai.ngo@oracle.com> Fixes:e4469c6cc6("NFSD: Fix the NFSv4.1 CREATE_SESSION operation") Tested-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.